The Lazarus Protocol: Rescue Catheter Ablation of Incessant Ventricular Fibrillation by Purkinje Substrate Denetworking in Critically Ill Patients With Ischemic Cardiomyopathy.

We report a case series of 3 critically ill patients with refractory incessant ventricular fibrillation (VF) who underwent catheter ablation using high-density mapping of the Purkinje system during ongoing VF, combined with targeted Purkinje denetworking and myocardial substrate modification. All patients were supported with advanced mechanical circulatory support, including venoarterial extracorporeal membrane oxygenation or venoarterial extracorporeal membrane oxygenation with Impella support, and procedures were guided by electroanatomic mapping with multimodality imaging integration. Purkinje potentials and abnormal electrograms within infarcted and border-zone myocardium were targeted, resulting in restoration and maintenance of sinus rhythm with no inducible ventricular arrhythmias after ablation. These findings suggest that, in carefully selected patients, combined Purkinje-targeted ablation and substrate modification may provide a life-saving rescue strategy for otherwise refractory incessant VF.